The objective is to determine whether problem lists can supplement or supplant diagnosis as predictors of patterns of treatment and post-hospital outcome. Positive results would be of considerable value to the utilization review process and be of long-term help to the function of the Professional Standards Review Organization (PSRO). A classificational system for coding problem lists will be developed and applied to the problem oriented records of Butler Hospital. Problem clusters will be sought; problems and problem clusters will be correlated with diagnoses; both diagnoses and problems will be used to predict treatment variables. Post treatment assessments of patient outcome will be completed to prepare for studies of the interrelationship of problem, treatment and outcome.